Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Nat Commun ; 15(1): 3213, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38615060

RESUMO

Oxidative stress-induced lipid accumulation is mediated by lipid droplets (LDs) homeostasis, which sequester vulnerable unsaturated triglycerides into LDs to prevent further peroxidation. Here we identify the upregulation of lipopolysaccharide-binding protein (LBP) and its trafficking through LDs as a mechanism for modulating LD homeostasis in response to oxidative stress. Our results suggest that LBP induces lipid accumulation by controlling lipid-redox homeostasis through its lipid-capture activity, sorting unsaturated triglycerides into LDs. N-acetyl-L-cysteine treatment reduces LBP-mediated triglycerides accumulation by phospholipid/triglycerides competition and Peroxiredoxin 4, a redox state sensor of LBP that regulates the shuttle of LBP from LDs. Furthermore, chronic stress upregulates LBP expression, leading to insulin resistance and obesity. Our findings contribute to the understanding of the role of LBP in regulating LD homeostasis and against cellular peroxidative injury. These insights could inform the development of redox-based therapies for alleviating oxidative stress-induced metabolic dysfunction.


Assuntos
Proteínas de Fase Aguda , Gotículas Lipídicas , Glicoproteínas de Membrana , Proteínas de Fase Aguda/metabolismo , Proteínas de Transporte/metabolismo , Homeostase , Gotículas Lipídicas/metabolismo , Lipopolissacarídeos/metabolismo , Glicoproteínas de Membrana/metabolismo , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Triglicerídeos
2.
Int J Mol Sci ; 24(23)2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38069199

RESUMO

The liver is the primary organ accountable for complex physiological functions, including lipid metabolism, toxic chemical degradation, bile acid synthesis, and glucose metabolism. Liver function homeostasis is essential for the stability of bodily functions and is involved in the complex regulation of the balance between cell proliferation and cell death. Cell proliferation-halting mechanisms, including autophagy and senescence, are implicated in the development of several liver diseases, such as cholestasis, viral hepatitis, nonalcoholic fatty liver disease, liver fibrosis, and hepatocellular carcinoma. Among various cell death mechanisms, autophagy is a highly conserved and self-degradative cellular process that recycles damaged organelles, cellular debris, and proteins. This process also provides the substrate for further metabolism. A defect in the autophagy machinery can lead to premature diseases, accelerated aging, inflammatory state, tumorigenesis, and cellular senescence. Senescence, another cell death type, is an active player in eliminating premalignant cells. At the same time, senescent cells can affect the function of neighboring cells by secreting the senescence-associated secretory phenotype and induce paracrine senescence. Autophagy can promote and delay cellular senescence under different contexts. This review decodes the roles of autophagy and senescence in multiple liver diseases to achieve a better understanding of the regulatory mechanisms and implications of autophagy and senescence in various liver diseases.


Assuntos
Envelhecimento , Hepatopatia Gordurosa não Alcoólica , Humanos , Envelhecimento/metabolismo , Senescência Celular/genética , Autofagia/genética
3.
Genes Dis ; 10(5): 1883-1893, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37492717

RESUMO

Cellular metabolism-induced epigenetic regulation is essential for the maintenance of cellular homeostasis. Nicotinamide N-methyltransferase (NNMT) is emerging as a key point of intersection between cellular metabolism and epigenetic regulation and has a central role in various physiological and pathological processes. NNMT catalyzes the methylation of nicotinamide (NAM) using the universal methyl donor S-adenosyl methionine (SAM) to yield S-adeno-syl-L-homocysteine (SAH) and N1-methylnicotinamide (MNAM), directly linking methylation balance with nicotinamide adenosine dinucleotide (NAD+) contents. NNMT acts on either the SAM-methylation balance or both NAD+ metabolism, depending on the tissue involved or pathological settings where metabolic demand is increased. Under physiological conditions, the liver act as an essential metabolic organ with abundant NNMT expression, while NNMT hepatic function is not mediated by its methyltransferase activity due to other major methyltransferases such as glycine N-methyltransferase (GNMT) in the liver. However, hepatic NNMT, as well as its metabolite is improperly regulated and linked to the worse pathological states in liver diseases, including alcoholic liver disease, non-alcoholic fatty liver disease (NAFLD), liver cirrhosis, and hepatocellular carcinoma (HCC), suggesting a potential role in the process of liver diseases. In this review, we summarize how NNMT regulates cell methylation balance and NAD metabolism, and extensively outline the current knowledge concerning the functions of NNMT in hepatic metabolism including glucose, lipid and energy, with a specific focus on the contribution of NNMT to the pathophysiology of liver-related diseases. NNMT is involved in the development and progression of liver diseases. Understanding the complex NNMT regulatory network and its effects on pathogenesis could provide new therapeutic strategies in the context of liver diseases.

4.
Basic Clin Pharmacol Toxicol ; 130(2): 268-276, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34806331

RESUMO

Progesterone is an important natural hormone regulating ovulation and menstruation. The present study aimed to investigate the pharmacokinetics and safety of two formulations of progesterone in Chinese postmenopausal females under fasting and fed conditions. The study adopted a single-dose, open-label, randomized, three-period bioequivalence design. A total of 96 subjects were enrolled and randomly assigned to the fasting cohort or fed cohort. A high-fat meal (890 kcal) was used in the fed study. The reference-scaled average bioequivalence method was used for bioequivalence evaluation. A high-fat meal led to a 22-fold higher peak concentration (Cmax ) and a 7-fold higher area under the curve (AUC) while time to reach Cmax and half-life was not significantly affected. The concentration-time curve displayed double peaks suggesting the existence of enterohepatic circulation. The test/reference geometric mean ratios for Cmax and AUC under fasting and fed conditions are all within the range of 80% to 125%. All adverse events (AEs) that occurred during the trial were mild and did not cause drop-out, though these AEs occurred more frequently under fed state. In conclusion, the two formulations of progesterone are bioequivalent in Chinese subjects under fasting and fed conditions. Drug label modification regarding food effects needs further discussion.


Assuntos
Interações Alimento-Droga , Pós-Menopausa , Progesterona/administração & dosagem , Progestinas/administração & dosagem , Área Sob a Curva , Povo Asiático , Estudos de Coortes , Gorduras na Dieta , Jejum , Feminino , Meia-Vida , Humanos , Pessoa de Meia-Idade , Progesterona/efeitos adversos , Progesterona/farmacocinética , Progestinas/efeitos adversos , Progestinas/farmacocinética , Equivalência Terapêutica
5.
Aging Cell ; 21(1): e13532, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34905649

RESUMO

The "rejuvenating" effect of growth differentiation factor 11 (GDF11) is called into question recently, and its role, as well as plausible signaling mechanisms in liver senescence, is unclear. To overexpress or knockdown GDF11, aged male mice are injected with a single dose of adeno-associated viruses-GDF11 or adenovirus-small hairpin RNA-GDF11, respectively. GDF11 overexpression significantly accelerates liver senescence in aged mice, whereas GDF11 knockdown has opposite effects. Concomitantly, autophagic flux is impaired in livers from GDF11 overexpression mice. Conversely, GDF11 knockdown increases autophagic flux. Moreover, rapamycin successfully restores the impaired autophagic flux and alleviates liver senescence in GDF11 overexpression mice, while the GDF11 knockdown-mediated benefits are abolished by the autophagy inhibitor bafilomycin A1. GDF11 leads to a drop in lysosomal biogenesis resulting in defective autophagic flux at autophagosome clearance step. Mechanistically, GDF11 significantly activates mammalian target of rapamycin complex 1 (mTORC1) and subsequently represses transcription factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy. Inhibition of mTORC1 or TFEB overexpression rescues the GDF11-impaired autophagic flux and cellular senescence. Hepatocyte-specific deletion of GDF11 does not alter serum GDF11 levels and liver senescence. Collectively, suppression of autophagic activity via mTORC1/TFEB signaling may be a critical molecular mechanism by which GDF11 exacerbates liver senescence. Rather than a "rejuvenating" agent, GDF11 may have a detrimental effect on liver senescence.


Assuntos
Autofagia/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Fatores de Diferenciação de Crescimento/metabolismo , Fígado/patologia , Lisossomos/efeitos dos fármacos , Animais , Senescência Celular , Humanos , Masculino , Camundongos
6.
Front Immunol ; 12: 681810, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34295331

RESUMO

Inflammation, which is induced by the immune response, is recognized as the driving factor in many diseases, including infections and inflammatory diseases, metabolic disorders and cancers. Genetic variations in pivotal genes associated with the immune response, particularly single nucleotide polymorphisms (SNPs), may account for predisposition and clinical outcome of diseases. Lipopolysaccharide (LPS)-binding protein (LBP) functions as an enhancer of the host response to LPS, the main component of the outer membrane of gram-native bacteria. Given the crucial role of LBP in inflammation, we will review the impact of SNPs in the LBP gene on infections and inflammatory diseases, metabolic disorders and cancers.


Assuntos
Proteínas de Fase Aguda/genética , Proteínas de Transporte/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Glicoproteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Proteínas de Fase Aguda/metabolismo , Alelos , Animais , Proteínas de Transporte/metabolismo , Doenças Transmissíveis/etiologia , Doenças Transmissíveis/metabolismo , Genótipo , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Glicoproteínas de Membrana/metabolismo , Doenças Metabólicas/diagnóstico , Doenças Metabólicas/genética , Doenças Metabólicas/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia
8.
Clin Sci (Lond) ; 133(20): 2069-2084, 2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31654062

RESUMO

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor (TGF)-ß superfamily. The rejuvenative effect of GDF11 has been called into question recently, and its role in liver regeneration is unclear. Here, we investigated the pathophysiologic role of GDF11, as well as its plausible signaling mechanisms in a mouse model of partial hepatectomy (PH). We demonstrated that both serum and hepatic GDF11 protein expression increased following PH. Treatment with adeno-associated viruses-GDF11 and recombinant GDF11 protein severely impaired liver regeneration, whereas inhibition of GDF11 activity with neutralizing antibodies significantly improved liver regeneration after PH. In vitro, GDF11 treatment significantly delayed cell proliferation and induced cell-cycle arrest in α mouse liver 12 (AML12) cells. Moreover, GDF11 activated TGF-ß-SMAD2/3 signaling pathway. Inhibition of GDF11-induced SMAD2/3 activity significantly blocked GDF11-mediated reduction in cell proliferation both in vivo and in vitro. In the clinical setting, GDF11 levels were significantly elevated in patients after hepatectomy. Collectively, these results indicate that rather than a 'rejuvenating' agent, GDF11 impairs liver regeneration after PH. Suppression of cell-cycle progression via TGF-ß-SMAD2/3 signaling pathway may be a key mechanism by which GDF11 inhibits liver regeneration.


Assuntos
Proteínas Morfogenéticas Ósseas/fisiologia , Fatores de Diferenciação de Crescimento/fisiologia , Regeneração Hepática/fisiologia , Animais , Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Proteínas Morfogenéticas Ósseas/sangue , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Fatores de Diferenciação de Crescimento/antagonistas & inibidores , Fatores de Diferenciação de Crescimento/sangue , Fatores de Diferenciação de Crescimento/metabolismo , Fatores de Diferenciação de Crescimento/farmacologia , Hepatectomia , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Humanos , Fígado/metabolismo , Fígado/patologia , Regeneração Hepática/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Período Pós-Operatório , Proteínas Recombinantes/farmacologia , Transdução de Sinais/fisiologia , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo
9.
J Immunol Res ; 2018: 6085095, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30525057

RESUMO

INTRODUCTION: Sepsis is the primary cause of death from infection. We wanted to improve the outcome of sepsis by stimulating innate immunity in combination with modulating the severity of inflammatory responses in rats. METHOD: Sepsis was induced by the injection of feces suspension (control). A 5-day course of G-CSF treatment was given before the septic insult (G-CSF). The inflammatory response was decreased using various doses of the LPS-blocking peptide LBPK95A (5 mg/kg = 100% Combi group, 0.5 mg/kg = 10% Combi group, and 0.05 mg/kg = 1% Combi group). Survival rates were observed. Bacterial clearance, neutrophil infiltration, tissue damage, and the induction of hepatic and systemic inflammatory responses were determined 2 h and 12 h after the septic insult. RESULTS: High-dose LBPK95A (100% Combi) reduced the survival rate to 10%, whereas low-dose LBPK95A (10% and 1% Combi) increased the survival rates to 50% and 80%, respectively. The survival rates inversely correlated with multiorgan damage as indicated by the serum levels of ALT and urea. G-CSF treatment increased the white blood cell counts, hepatic neutrophil infiltration, and bacterial clearance in the liver, lung, and blood. The blockade of the LPS-LBP interaction decreased neutrophil infiltration, led to increased white blood cell count, and decreased hepatic neutrophil infiltration, irrespective of dose. However, bacterial clearance improved in the 1% and 10% Combi groups but worsened in the 100% Combi group. G-CSF increased TNF-α and IL-6 levels. Irrespective of dose, the blockade of the LPS-LBP interaction was associated with low systemic cytokine levels and delayed increases in hepatic TNF-α and IL-6 mRNA expression. The delayed increase in cytokines was associated with the phosphorylation of STAT3 and AKT. CONCLUSION: Our results revealed that increasing innate immunity by G-CSF pretreatment and decreasing inflammatory responses using LBPK95A improved the survival rates in a rat sepsis model and could be a novel strategy to treat sepsis.


Assuntos
Fator Estimulador de Colônias de Granulócitos/imunologia , Inflamação/imunologia , Peptídeos/imunologia , Sepse/imunologia , Animais , Modelos Animais de Doenças , Regulação da Expressão Gênica , Humanos , Imunidade Inata , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolissacarídeos/antagonistas & inibidores , Masculino , Infiltração de Neutrófilos , Peptídeos/farmacologia , Ratos , Ratos Endogâmicos Lew , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
10.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 30(6): 583-587, 2018 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-30009736

RESUMO

OBJECTIVE: To investigate the effects of nicotinamide phosphoribosyl transferase (NAMPT) inhibitor FK866 on polymicrobial sepsis-induced liver injury in mice. METHODS: Eighty-four healthy male C57BL/6J mice were divided into four groups by random number table method (n = 21): sham group, sepsis-induced liver injury model by cecal ligation and perforation group (CLP group), vehicle+CLP group and FK866+CLP group. FK866 (10 mg/kg) or same volume dimethyl sulfoxide were given intraperitoneally into mice 24, 12 and 0.5 hours prior to CLP in the FK866+CLP group or the vehicle+CLP group, respectively. Fifteen mice in each group were used to observe the 48-hour survival after operation. The remaining 6 mice were sacrificed 20 hours after operation to harvest venous blood and liver tissue samples for index detection. The levels of serum alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured by colorimetry; the levels of serum NAMPT, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by enzyme linked immunosorbent assay (ELISA); the mRNA expressions of TNF-α and IL-6 were measured by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR); the protein expressions of hepatic NAMPT, cytoplasmic IκBα and nuclear factor-κB (NF-κB) were measured by Western Blot. RESULTS: Compared with the sham group, the 48-hour survival in the CLP group was significantly decreased; serum and liver NAMPT protein levels were significantly increased, serum ALT, AST, TNF-α, IL-6 levels and mRNA expressions of TNF-α, IL-6 in liver tissue were significantly increased; the expression of cytoplasmic IκBα protein was significantly decreased, and the expression of nuclear NF-κB protein was significantly increased; which indicated that CLP induced NF-κB activation, inflammation and liver injury. There was no significant difference between the vehicle+CLP group and the CLP group. Compared with the vehicle+CLP group, the 48-hour survival in FK866+CLP group was significantly increased (53.33% vs. 26.67%); serum ALT, AST, TNF-α, IL-6 levels and mRNA expressions of TNF-α, IL-6 in liver tissue were significantly decreased [serum ALT (U/L): 128.94±32.48 vs. 237.24±58.61, serum AST (U/L): 289.89±68.74 vs.468±82.17, serum TNF-α (pg/L): 65.17±18.74 vs.127.64±48.18, serum IL-6 (ng/L): 31.78±5.23 vs. 60.87±13.12, liver TNF-α mRNA (2-ΔΔCt): 8.37±4.17 vs. 18.24±6.12, liver IL-6 mRNA (2-ΔΔCt): 18.58±7.12 vs.34.24±6.71], the expression of cytoplasmic IκBα protein was significantly increased (IκBα/GAPDH: 0.23±0.03 vs. 0.12±0.04), while expression of nuclear NF-κB protein was significantly decreased (NF-κB/Lamin B1: 0.25±0.04 vs. 0.42±0.05), with statistically significant differences (all P < 0.05). CONCLUSIONS: NAMPT inhibitor FK866 protects polymicrobial sepsis-induced liver injury via the inhibition of NF-κB activation and inflammation.


Assuntos
Fígado/lesões , Sepse , Animais , Aspartato Aminotransferases , Interleucina-6 , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator de Necrose Tumoral alfa
11.
Aging Cell ; 17(1)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29210183

RESUMO

Recent studies showing the therapeutic effect of young blood on aging-associated deterioration of organs point to young blood as the solution for clinical problems related to old age. Given that defective autophagy has been implicated in aging and aging-associated organ injuries, this study was designed to determine the effect of young blood on aging-induced alterations in hepatic function and underlying mechanisms, with a focus on autophagy. Aged rats (22 months) were treated with pooled plasma (1 ml, intravenously) collected from young (3 months) or aged rats three times per week for 4 weeks, and 3-methyladenine or wortmannin was used to inhibit young blood-induced autophagy. Aging was associated with elevated levels of alanine transaminase and aspartate aminotransferase, lipofuscin accumulation, steatosis, fibrosis, and defective liver regeneration after partial hepatectomy, which were significantly attenuated by young plasma injections. Young plasma could also restore aging-impaired autophagy activity. Inhibition of the young plasma-restored autophagic activity abrogated the beneficial effect of young plasma against hepatic injury with aging. In vitro, young serum could protect old hepatocytes from senescence, and the antisenescence effect of young serum was abrogated by 3-methyladenine, wortmannin, or small interfering RNA to autophagy-related protein 7. Collectively, our data indicate that young plasma could ameliorate age-dependent alterations in hepatic function partially via the restoration of autophagy.


Assuntos
Envelhecimento/fisiologia , Autofagia/fisiologia , Hepatócitos/fisiologia , Regeneração Hepática/fisiologia , Animais , Fígado Gorduroso/metabolismo , Hepatectomia/métodos , Fígado/metabolismo , Masculino , Ratos Sprague-Dawley
12.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 29(3): 228-232, 2017 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-28627342

RESUMO

OBJECTIVE: To investigate the effects of baicalein (Bai) on acute lung injury (ALI) induced by intestinal ischemia/reperfusion (I/R) and its mechanism in mice. METHODS: Twenty-four male C57BL/6J mice were divided into three groups by random number table: namely sham group, I/R group and Bai+I/R group, with 8 mice in each group. Intestinal I/R induced lung injury model was reproduced by clamping superior mesenteric artery for 90 minutes, followed by reperfusion. Bai (100 mg/kg) was intraperitoneally injected 1 hour before ischemic challenge in the Bai+I/R group. The mice in sham group underwent the similar procedure with I/R group but without vascular occlusion. All mice were sacrificed at 4 hours of reperfusion, and blood was collected from inferior vena cava and lung tissues were harvested. Lung tissues were stained with hematoxylin-eosin (HE), and histological changes were examined under light microscope for pathological score. Lung wet/dry (W/D) ratio was calculated. Lung cell apoptosis was determined by TdT-mediated dUTP nick end labeling (TUNEL) technique. Serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by enzyme-linked immunosorbent assay (ELISA). The mRNA expressions of TNF-α and IL-6 in lung tissues were determined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). The protein expression levels of cytoplasmic inhibitory factor-α of nuclear factor-κB (IκB-α) and nucleus NF-κB were determined by Western Blot. RESULTS: Under light microscope, a normal lung tissue structure was shown in the sham group and no evidence of obvious lung injury was found. In the I/R group, the alveolar structure was seriously damaged. The alveolar wall was widened and there was significant interstitial edema and leukocytes infiltration. In the Bai+I/R group, pathological damage was significantly decreased as indicated by reduced lung tissue edema and leukocytes infiltration. Compared with the sham group, the lung pathological scores, W/D ratio and cellular apoptosis in the I/R group were significantly increased. Both serum TNF-α and IL-6 contents and lung TNF-α and IL-6 mRNA expressions were significantly increased. Furthermore, I/R significantly resulted in a decrease of IκB-α in the cytoplasm and an increase of NF-κB in the nucleus. Notably, Bai treatment significantly attenuated ALI induced by intestinal I/R injury. Compared with the I/R group, the lung pathological scores and W/D ratio in the Bai+I/R group were significantly decreased (lung pathological score: 4.59±1.17 vs. 6.27±1.34, W/D ratio: 3.79±0.28 vs. 4.32±0.57), cellular apoptosis was significantly decreased [(4.85±2.47)% vs. (8.15±2.33)%], both serum TNF-α and IL-6 contents and lung TNF-α and IL-6 mRNA expressions were significantly decreased [serum TNF-α (pg/L): 124.18±30.49 vs. 167.72±38.65, IL-6 (ng/L): 1.65±0.69 vs. 2.43±0.57; lung TNF-α mRNA (2-ΔΔCt): 4.75±2.38 vs. 7.69±2.32, IL-6 mRNA (2-ΔΔCt): 16.45±4.39 vs. 27.69±6.82], additionally, Bai pretreatment significantly increased cytoplasmic IκB-α protein expression (gray value: 0.47±0.11 vs. 0.27±0.09), while decreased nuclear NF-κB protein expression (gray value: 0.57±0.13 vs. 1.07±0.14, all P < 0.05). CONCLUSIONS: Bai could attenuate intestinal I/R injury induced ALI via the inhibition of inflammation and apoptosis.


Assuntos
Lesão Pulmonar Aguda , Animais , Flavanonas , Pulmão , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B , Fator de Necrose Tumoral alfa
13.
Obesity (Silver Spring) ; 25(3): 561-571, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28145056

RESUMO

OBJECTIVE: 1,25(OH)2 D3 has been reported to attenuate liver steatosis; however, its exact mechanism of action remains poorly understood. This study aimed to determine whether 1,25(OH)2 D3 can attenuate hepatic steatosis by inducing autophagy. METHODS: Male C57BL/6 mice fed a high-fat diet (HFD) were injected with 1,25(OH)2 D3 for 4 weeks. These mice were given 3-methyladenine (3-MA) to inhibit autophagy. HepG2 cells were preincubated with a free fatty acid (FFA) and then treated with 1,25(OH)2 D3 . Vitamin D receptor (VDR) shRNA and autophagy-related 16-like 1 (ATG16L1) siRNA were used for VDR knockdown or ATG16L1 silencing, respectively. RESULTS: 1,25(OH)2 D3 diminished HFD-induced liver damage and steatosis, changes accompanied by autophagy and ATG16L1 expression upregulation. Inhibition of 1,25(OH)2 D3 -induced autophagy mediated by 3-MA blocked the protective effects of 1,25(OH)2 D3 on hepatic steatosis. Additionally, 1,25(OH)2 D3 -induced autophagy appeared to play a role in anti-inflammation and lipid metabolism modulation in the liver. In HepG2 cells, 1,25(OH)2 D3 reduced lipid accumulation and increased autophagy and ATG16L1 expression; however, this effect was abrogated after VDR knockdown. The protective effects of 1,25(OH)2 D3 -mediated autophagy against lipid accumulation were abolished by 3-MA. Furthermore, siRNA-mediated ATG16L1 knockdown prevented 1,25(OH)2 D3 -induced autophagy, resulting in increased fat accumulation. CONCLUSIONS: The data suggest that 1,25(OH)2 D3 may ameliorate hepatic steatosis by inducing autophagy by upregulating ATG16L1.


Assuntos
Autofagia/efeitos dos fármacos , Calcitriol/farmacologia , Ácidos Graxos não Esterificados/farmacologia , Fígado Gorduroso/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Adenina/análogos & derivados , Adenina/farmacologia , Animais , Proteínas Relacionadas à Autofagia , Calcitriol/uso terapêutico , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Dieta Hiperlipídica , Fígado Gorduroso/genética , Fígado Gorduroso/metabolismo , Inativação Gênica , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Interferente Pequeno , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Regulação para Cima
14.
Mol Med Rep ; 12(3): 4071-4078, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26062578

RESUMO

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. Hematopoietic cell­specific protein 1­associated protein X­1 (HAX­1) has been found to be involved in several types of cancer. However, the role of HAX­1 in CRC remains to be elucidated. The aim of the present study was to investigate whether the expression of HAX­1 is associated with the progression of CRC, and to determine the effects of HAX­1 on the apoptosis and proliferation of CRC cells. Tumor tissues and adjacent noncancerous tissues were collected from 60 patients with CRC, following the provision of informed consent. The expression levels of HAX­1 and the association with clinical and pathological characteristics were then analyzed. The expression levels of HAX­1 were significantly higher in the cancerous tissues from the patients with CRC, particularly in tissues of an advanced stage of cancer. In addition, HAX­1 expression was associated with malignant progression and poor prognosis. Furthermore, SW480 CRC cells, overexpressing HAX­1, exhibited increased resistance to camptothecin in vitro, and promoted proliferation in vitro and in vivo. By contrast, HAX­1 knockdown significantly decreased the proliferation. In addition, the expression levels of ki­67 and phosphorylated­akt were inhibited following HAX­1 knockdown. In conclusion, the expression levels of HAX­1 were increased in cancerous tissue from patients with CRC, and were associated with progression of the disease. These results suggested that HAX­1 may contribute to chemotherapy resistance and malignant progression in CRC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/genética , Idoso , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Prognóstico , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transplante Heterólogo
15.
Shock ; 43(5): 497-503, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25874537

RESUMO

The effect of granulocyte colony-stimulating factor (G-CSF) on sepsis is discussed controversially in clinical studies. We previously demonstrated that G-CSF treatment induced lipopolysaccharide (LPS) sensitization via up-regulation of LPS-binding protein (LBP). We hypothesized that the futile effect of G-CSF-treatment in sepsis might be due to its ability to up-regulate LBP. Therefore, blockade of LBP may attenuate the G-CSF-induced LPS sensitization and protect animals from polymicrobial sepsis. Endogenous LBP levels were up-regulated by pretreatment with G-CSF, and the LBP protein was blocked by administration of a specific blocking peptide-LBPK95A. Polymicrobial sepsis was induced by intraperitoneal injection of feces slurry. Rats were monitored every 3 up to 72 h to observe the survival rate. Tissue injury, bacterial infiltration, local inflammatory response, and neutrophil infiltration at 0, 2, and 12 h after the septic insult were analyzed. The survival benefit of G-CSF pretreatment was improved when combined with LBPK95A treatment (control vs. G-CSF vs. combi: 36% vs. 56% vs. 93%; P < 0.05). Combined treatment of G-CSF and LBPK95A was associated with the minimal tissue damage. Treatment with LBPK95A significantly inhibited the neutrophil infiltration without interfering with the bacterial clearance. The G-CSF-induced inflammatory sensitization effect was inhibited by LBPK95A, indicated by the decrease of cytokines expression, and the activation of nuclear factor kappa B and signal transducer and activator of transcription 3 signaling pathway. In conclusion, these results suggested that the effect of prophylactic augmentation of the host's response via G-CSF pretreatment was further enhanced by inhibition of the up-regulation of LBP.


Assuntos
Proteínas de Fase Aguda/química , Proteínas de Transporte/química , Fator Estimulador de Colônias de Granulócitos/química , Glicoproteínas de Membrana/química , Animais , Fezes , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Humanos , Inflamação , Masculino , NF-kappa B/metabolismo , Neutrófilos/imunologia , Neutrófilos/patologia , Peptídeos/administração & dosagem , Ratos , Ratos Endogâmicos Lew , Fator de Transcrição STAT3/metabolismo , Sepse/imunologia , Sepse/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Regulação para Cima
16.
Int Immunopharmacol ; 24(1): 72-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25479717

RESUMO

Ischemia/reperfusion (I/R) is a pathophysiologic process that occurs during hemorrhagic shock, liver resection and liver transplantation. Baicalein, the main active ingredient of the Scutellaria root, exerts anti-inflammatory and anti-apoptotic properties in the setting of I/R injury in the heart and brain. However, the role of baicalein in liver I/R injury and its regulatory mechanisms remain poorly understood. This study was designed to evaluate the effects of baicalein in a model of liver I/R in mice and to explore the possible mechanisms. Baicalein (100mg/kg) was intraperitoneally injected 1h before warm ischemia. Pretreatment with baicalein protected against liver I/R injury, as indicated by the decreased serum aminotransferase levels and the reduced histopathologic abnormalities. Baicalein also significantly reduced cellular hepatic apoptosis in response to I/R injury. Moreover, pretreatment with baicalein significantly inhibited nuclear factor-kappa B (NF-κB) activation and the subsequent proinflammatory cytokine production, and decreased leukocyte infiltration. In vitro studies, baicalein treatment inhibited the proinflammatory cytokine production via the modulation of NF-κB signaling pathway in lipopolysaccharide-stimulated macrophages. Taken together, these results suggest that baicalein could protect against liver I/R injury via inhibition of inflammation by down-regulating NF-κB activity, and suppression of cellular hepatic apoptosis.


Assuntos
Antioxidantes/administração & dosagem , Flavanonas/administração & dosagem , Fígado/irrigação sanguínea , Fígado/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Traumatismo por Reperfusão/prevenção & controle , Alanina Transaminase/sangue , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Creatinina/sangue , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Lipopolissacarídeos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais/efeitos dos fármacos
17.
J Immunol Res ; 2015: 187048, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26798659

RESUMO

Sepsis and SIRS (systemic inflammatory response syndrome) belong to a severe disease complex characterized by infection and/or a whole-body inflammatory state. There is a growing body of evidence that neutrophils are actively involved in sepsis and are responsible for both release of cytokines and phagocytosis of pathogens. The neutrophil level is mainly regulated by G-CSF, a cytokine and drug, which is widely used in the septic patient with neutropenia. This review will briefly summarize the role of neutrophils and the therapeutic effect of G-CSF in sepsis. We further suggest that targeting neutrophil function to modulate the balance between innate immunity and inflammatory injury could be a worthwhile therapeutic strategy for sepsis.


Assuntos
Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Imunidade Inata/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Sepse/tratamento farmacológico , Síndrome de Resposta Inflamatória Sistêmica/tratamento farmacológico , Proteínas de Fase Aguda/antagonistas & inibidores , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/imunologia , Animais , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Modelos Animais de Doenças , Regulação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos/genética , Fator Estimulador de Colônias de Granulócitos/imunologia , Humanos , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/imunologia , Camundongos , NF-kappa B/genética , NF-kappa B/imunologia , Neutrófilos/imunologia , Neutrófilos/patologia , Fagocitose/efeitos dos fármacos , Sepse/genética , Sepse/imunologia , Sepse/patologia , Síndrome de Resposta Inflamatória Sistêmica/genética , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Síndrome de Resposta Inflamatória Sistêmica/patologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
18.
Mediators Inflamm ; 2014: 629507, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25525303

RESUMO

Liver dysfunction has been known to occur frequently in cases of sepsis. Excessive inflammation and apoptosis are pathological features of acute liver failure. Recent studies suggest that activation of glycogen synthase kinase- (GSK-) 3ß is involved in inflammation and apoptosis. We aimed to investigate the protective effects of GSK-3ß inhibition on polymicrobial sepsis-induced liver injury and to explore the possible mechanisms. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP), and SB216763 was used to inhibit GSK-3ß in C57BL/6 mice. GSK-3ß was activated following CLP. Administration of SB216763 decreased mortality, ameliorated liver injury, and reduced hepatic apoptosis. The inhibition of GSK-3ß also reduced leukocyte infiltration and hepatic inflammatory cytokine expression and release. Moreover, GSK-3ß inhibition suppressed the transcriptional activity of nuclear factor-kappa B (NF-κB) but enhanced the transcriptional activity of cAMP response element binding protein (CREB) in the liver. In in vitro studies, GSK-3ß inhibition reduced inflammatory cytokine production via modulation of NF-κB and CREB signaling pathways in lipopolysaccharide-stimulated macrophages. In conclusion, these findings suggest that GSK-3ß blockade protects against CLP-induced liver via inhibition of inflammation by modulating NF-κB and CREB activity and suppression of hepatic apoptosis.


Assuntos
Apoptose , Quinase 3 da Glicogênio Sintase/metabolismo , Inflamação/metabolismo , Fígado/patologia , Animais , Linhagem Celular , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Glicogênio Sintase Quinase 3 beta , Imuno-Histoquímica , Indóis/química , Interleucina-6/metabolismo , Leucócitos/citologia , Fígado/lesões , Fígado/metabolismo , Masculino , Maleimidas/química , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Peroxidase/metabolismo , Transdução de Sinais
19.
Histochem Cell Biol ; 142(6): 667-76, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25059648

RESUMO

Liver dysfunction is a serious complication in the early phase following major liver resection or liver transplantation and might be aggravated by the translocation of bacteria and lipopolysaccharide (LPS). As a preventive strategy, granulocyte colony-stimulating factor (G-CSF) is prophylactically applied in patients who are subjected to major surgery. However, we previously demonstrated that G-CSF can induce LPS sensitization. In this study, we aimed to evaluate the effects of G-CSF pretreatment on hepatic microcirculatory disturbances and postoperative liver dysfunction after 70 % partial hepatectomy (PH) in rats. PH alone was well tolerated by all animals (100 % survival rate, slight liver damage and inflammation). LPS application after 70 % PH caused moderate inflammation, microcirculatory disturbances and hepatic damage and led to a 24-h survival rate of 30 % after the operations. In the G-CSF-LPS-PH group, all of the rats died within 4 h with severe inflammatory responses and liver damage (i.e., pronounced erythrocyte congestion and neutrophil infiltration). Portal hypertension and microcirculatory disorders (i.e., inhomogeneous perfusion, sinusoidal dilatation and reductions on functional capillary density) were more pronounced in the G-CSF-LPS-PH group. In conclusion, increased circulating LPS levels were associated with an imbalanced inflammatory response and microcirculatory dysfunction that preceded liver damage and subsequent dysfunction following surgery. G-CSF-pretreatment aggravated microcirculatory disturbances and liver damage, which might have been related to G-CSF-induced LPS sensitization.


Assuntos
Fator Estimulador de Colônias de Granulócitos/farmacologia , Hepatectomia , Lipopolissacarídeos/toxicidade , Hepatopatias/prevenção & controle , Fígado/efeitos dos fármacos , Microcirculação/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Interações Medicamentosas , Ensaio de Imunoadsorção Enzimática , Imuno-Histoquímica , Fígado/lesões , Fígado/cirurgia , Masculino , Ratos , Ratos Endogâmicos Lew
20.
Zhonghua Zhong Liu Za Zhi ; 36(2): 123-7, 2014 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-24796461

RESUMO

OBJECTIVE: To investigate the clinical value of serum anti-Ku86 in early detection of hepatocellular carcinoma (HCC). METHODS: Expression levels of Ku86 protein in HCC and adjacent normal liver tissues were detected by Western blotting. Serum anti-Ku86 level in 83 patients with early HCC and 124 patients with liver cirrhosis were detected by enzyme-linked immunosorbent assay (ELISA). Chemiluminescence was used to measure the serum level of α-fetoprotein (AFP). RESULTS: Expression of Ku86 protein in HCC was increased when compared with the adjacent normal liver tissues (0.21 ± 0.05 vs. 0.08 ± 0.02, P < 0.01). Serum anti-Ku86 level was significantly elevated in HCC patients compared with that in liver cirrhosis patients (0.47 ± 0.22 vs. 0.22 ± 0.06 Abs at 450 nm, P < 0.01), but there was no significant difference between HBV infection and HCV infection in HCC patients (0.51 ± 0.19 vs. 0.47 ± 0.24, P = 0.267). Of note, serum anti-Ku86 level was significantly decreased after surgical resection of the tumors in the 30 HCC cases tested (P < 0.01). The results of ROC analysis indicated a better performance of anti-Ku86 (0.857) than AFP (0.739) for early detection of HCC. In 83 HCC patients, the positive rate of anti-Ku86 was 61.4% (51/83), significantly higher than that of the AFP positive rate (27.7%, 23/83). The anti-Ku86 level was positive in 37 of 60 HCC cases with negative AFP. Combination assay of AFP and anti-Ku86 could detect 60 of 83 HCC cases (72.3%, 60/83). There was no significant correlation of anti-Ku86 and AFP (r = 0.156, P = 0.161). CONCLUSIONS: Serum anti-Ku86 level is significantly elevated and is not related to HBV and HCV infection in HCC patients. Serum anti-Ku86 antibody may be a potential biomarker for early detection of HCC, and can be used in combination with AFP in clinics.


Assuntos
Antígenos Nucleares/imunologia , Autoanticorpos/sangue , Carcinoma Hepatocelular/diagnóstico , Proteínas de Ligação a DNA/imunologia , Neoplasias Hepáticas/diagnóstico , Adulto , Idoso , Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/virologia , Detecção Precoce de Câncer , Feminino , Hepatite B/sangue , Hepatite C/sangue , Humanos , Autoantígeno Ku , Cirrose Hepática/sangue , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Curva ROC , alfa-Fetoproteínas/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA